Social Bookmarking is just a fancy name for talking about saving your bookmarks to the web instead of your computer. That way, youcan have your bookmarks anywhere you go. In most of these sites, it also allows you to link to other people's bookmarks and so on. It's a new way of networking and researching that is invaluable. Try it and you'll see.
Social Bookmark Sites:
del.icio.us
StumbleUpon
Blummy
Furl
Spurl